Lean body mass represents the fat-free component of your body weight. Knowing your LBM is essential for calculating precise nutritional requirements and evaluating strength training progress.
Lean Body Mass Calculator
Reviewed
ResultUpdates as you type
Lean Body Mass57.2 kg
Fat Mass17.8 kg
Lean Mass %%76.2
- Boer Formula
- 58.1 kg
- James Formula
- 59 kg
- Hume Formula
- 54.4 kg
Calculate your lean muscle mass and fat-free weight using the clinically validated Boer, James, and Hume formulas.
Calculate your lean body mass (fat-free weight) using the clinically validated Boer, James, and Hume equations.
How to use
- Choose your unit system (Metric or Imperial).
- Select your sex.
- Enter your height and weight.
- View your estimated Lean Body Mass and individual formula breakdowns.
Formula
Lean Body Mass (LBM) estimates total body weight excluding fat tissue.
Boer Formula (Male)
LBM = 0.407·weight(kg) + 0.267·height(cm) - 19.2Boer Formula (Female)
LBM = 0.252·weight(kg) + 0.473·height(cm) - 48.3James Formula (Male)
LBM = 1.1·weight(kg) - 128·(weight / height)²Frequently asked questions
What is Lean Body Mass (LBM)?
Lean Body Mass includes muscle, bone, organs, blood, and body water — everything except essential and storage fat.
Why is Lean Body Mass important for fitness?
LBM determines your basal metabolic rate and helps tailor protein and calorie targets for muscle building or cutting.